These are simpler than the other unit chests in that there are no internal pneumatics. Puffs mounted underneath serve to directly open the pallets. These were re-leathered and fitted with new phosphor bronze springs. The puff-boards were re-leathered and (latterly installed separately onto the main chest) fitted to the bottom of the chests as had been done originally. Sliders are fitted on top of the two chests for shutting off the reed ranks during tuning. In fact, that is detrimental to tuning accuracy: when the sliders are closed to allow wind to the helper rank only, those pipes receive more pressure than they do when the sliders are opened. Some of that wind is then diverted to the reeds, putting the helpers out-of-tune. However, for historical accuracy, the sliders are retained.
When it came to sorting out the wind trunking to these chests I found that they had been connected to the wrong channels in the main chest, where sits the wide channel and large pallet for the register ventil. It had been transposed with that of the violin register. The reason for this is unclear, but one possibility is that the wrong channel had been opened out and fitted with a supplementary ventil, by mistake. That had been done in 1990 (not by me, I hasten to add) to aid the wind supply to the saxophones and make them easier to tune. I never found this necessary on my numerous tunings of this organ after my original work on it. Suffice to say that I reverted the trunking to its original configuration.
The chests were given a coat of shellac on all external surfaces, and mounted in their correct positions on the main chest and their action thoroughly checked on the wind.